stainless +1mm exhaust valves.

[Aries_Turbo]

I have some stainless exhaust valves here at the house that came with a pile of parts from a friends acquistion and I had a question. I want to use them but I dont exactly know where they came from. they are swirl polished around the head and they only have one notch for the keeper like the intake valve.

i only ask cause I want to make sure that they arent the IMSA valve that the tips like to fail on. anyone have a description of the IMSA valve for me? I can take a pic of what i have if need be.

Brian

[Directconnection]

IMSA valve wouldn't be the +1mm, it would be the bigger 44mm valve.

I am sure there is credibility to the IMSA valves failing, but I know of several people that have had them w/out having issues. Unlike the S60 cam, I don't think they had a 100% failure rate.

Also, I thought the tips just eroded/flaked away on the ones people have seen? (menegon) Do they really break off and you toss a valve?

[Aries_Turbo]

i dont know all the stories but I know they were a risk... I dont like known risks. i like to create them myself lol.

Anyway, I took them over to my machinist and he didnt like the looks of them for a long range replacement as they were the stainless the whole way to the tip with no "cap" or whatever its called (little piece of tool steel that sorta looks like a thick thumbtack to prevent mushrooming and the like) so I just went with a stock style replacement. It should only need 2-3 exhaust valves max.

does anyone know offhand where I can get a slightly stiffer spring on a super short time table? either the part number of the one that menegon recommended or something similar? I dont want really stiff, I just want a little more stiff. :) Id prolly then get a valve height micrometer and some shims and set the installed height and do the calcs myself.

Brian

[Directconnection]

i dont know all the stories but I know they were a risk... I dont like known risks. i like to create them myself lol.

Anyway, I took them over to my machinist and he didnt like the looks of them for a long range replacement as they were the stainless the whole way to the tip with no "cap" or whatever its called (little piece of tool steel that sorta looks like a thick thumbtack to prevent mushrooming and the like) so I just went with a stock style replacement. It should only need 2-3 exhaust valves max.

does anyone know offhand where I can get a slightly stiffer spring on a super short time table? either the part number of the one that menegon recommended or something similar? I dont want really stiff, I just want a little more stiff. :) Id prolly then get a valve height micrometer and some shims and set the installed height and do the calcs myself.

Brian

Lash caps? I don't understand, stock valves don't have them so why would it matter with these other valves or are they starting to get out of shape?

[Aries_Turbo]

my stock ones are fine.... well except the bent one lol.

yeah lash caps. i dont know all the details but from what i gather the stainless doesnt like the beating from the follower like a harder carbon steel can handle. from what he says it will mushroom... or maybe chip away like the imsa?

from what I know about metallurgy stainless is softer so it seems feasible.

also, if i take a magnet to the valves i am running now... the stem is carbon steel, the head is a non magnetic stainless. they are SBI stock replacement.

Brian